基于小波变换与神经网络的石羊河流域夏季地温预测模型研究   总被引：1，自引：1，他引：0  

贾东于  李开明  聂晓英  袁春霞  李清峰  高福元 《冰川冻土》2020,42(2):412-422

地温变化在气候反馈效应中起着重要作用， 理解地温及其与影响因素之间的时空关系对预测全球温度变化至关重要。利用1998 - 2017年石羊河流域的逐日常规气象观测资料， 采用小波分析结合BP（Back Propagation）神经网络构建了石羊河流域夏季地温预报模型， 结果表明： 日平均地温预测效果在不同站点均为最佳， 其中预测值和观测值的相关系数均大于0.87， 3 ℃以内的预测概率均大于84%。其中， 民勤地区地温预测效果最好， 预测值和观测值的相关系数达到0.91， 3 ℃以内的预测概率达到86%。日最高地温的预测值与观测值的相关系数高于0.8， 但误差平方和、 标准差较大。永昌地区日最高地温的模拟效果最好， 3 ℃以内的预测概率达到83%。日最低地温的预测与观测值的平均相关系数高于0.66， 3 ℃以内的预报概率高于83%， 但预测值略低。其中， 武威地区日最低地温的预测效果最好， 预测值与观测值的相关系数为0.72， 3 ℃以内的预测概率达到94%。研究成果可为有效弥补干旱、 半干旱区地温观测资料缺失和探讨其与局地气候的关系提供一些参考。  相似文献   

非典型周期和气候突变的识别与判定          下载免费PDF全文

秦建国 《水文》2020,40(1):23-28

通过两种新方法分析了无锡站降水年际变化的突变性、周期性等特征,揭示了旱涝演化的自然规律。研究表明,1934、1978、2013年是我国近现代气候突变的临界点,这是旱涝演化的自然选择;无锡站年际降水的观测历史可分成四个特征不同的时段,每个时段节点对应的都是一次气候突变;气候突变会改变年际降水序列的一致性,分段法研究可以大幅度降低模拟难度、提高预测效率。发现并确认了3个气候突变点,实现了超长缺测中断期(13a)旱涝趋势的精确插补,完成了无锡站近百年降雨序列的周期性分析与旱涝趋势预测模拟,研究成果改变了近现代气候历史无法细分的现状。  相似文献   

山东大尹格庄金矿床深部三维定量成矿预测     

陈进  毛先成  邓浩 《地球学报》2020,41(2):179-191

大尹格庄金矿是胶西北招平断裂带中段的大型金矿床,但随着逐渐的开采其保有资源量不断下降,急需在矿床的深边部区域开展接续资源找矿工作。本文以大尹格庄金矿为研究对象,以区域成矿理论和找矿勘查模型为指导,利用三维地质建模技术构建了相关地质体的三维模型,在此基础上,采用定量化的方法提取地质体与成矿相关的控矿因素指标和矿化指标,并建立了三维定量成矿预测模型,并应用该模型圈定了3个找矿靶区。研究表明,该方法能够适用于大中型矿山的深边部找矿工作,其三维及定量化的预测结果能够为后续的勘探及开采工作提供重要参考。  相似文献   

基于均一化观测序列的成山头海表温度气候变化特征分析     

邹曙光  刘李钊  邹琰 《海洋技术学报》2019,38(6):51-55

文中利用加拿大环境部气候研究中心研发的惩罚最大t检验方法,选取均一的邻近气象站为参考站,结合元数据信息,对1960-2017年成山头海洋站海表温度序列进行了均一性检验与订正。利用订正后的海表温度序列对成山头海温气候变化特征进行分析。结果表明,订正前后年平均海表温度趋势发生了明显改变,表现出海温上升趋势较订正前加强的特征,增暖趋势由订正前的0.04℃/10 a上升到0.15℃/10 a,其中最暖的5个年份多发生在1980年以后,分别为1973年、1989年、2002年、2007年和2017年。海表温度总体呈显著上升趋势和明显的年代际波动,20世纪60年代至80年代末为偏冷阶段,之后开始增暖,20世纪90年代至今为偏暖阶段。1960-2017年,成山头的海温突变点在1987年,是一次增暖性突变,与中国大陆的气温突变特征和气温变化阶段性特征非常一致。  相似文献   

Obtaining the distribution of quiescent periods directly from the power spectral densities of Sea waves     

《Applied Ocean Research》2019

There is a growing practical interest in the ability to increase the sea states at which marine operations can be safely undertaken by exploiting the quiescent periods that are well known to exist under a wide range of sea conditions. While the actual prediction of quiescent periods at sea for the control of operations is a deterministic process, the long term planning of future maritime tasks that rely on these quiescent periods is a statistical process involving the anticipated quiescence properties of the forecasted sea conditions in the geographical region of interest. It is in principle possible to obtain such data in tabular form either large scale simulation or from field data. However, such simulations are computationally intensive and libraries of appropriate field data are not common. Thus, it is clearly attractive to develop techniques that exploit standard wave spectral models for describing the quiescence statistics directly from such spectra. The present study focuses upon such techniques and is a first step towards the production of a computationally low-cost quiescence prediction tool and compares its efficacy against simulations. Two significant properties emerge for a large class of wave spectral models that encompasses the ubiquitous Neumann and Pierson Moskowitz or Bretschneider forms. Firstly, the auto-correlation function of the wave profile that are required to produce the quiescence property can be obtained analytically in terms of standard special functions. This considerably reduces the computational cost making desktop computer-based planning tools a reality. Secondly, for each class of these parametric spectra, the probability of a given number of consecutive wave heights (normalised to the significant wave heights) less than some critical value is in fact independent of absolute wave height. Thus, for a broad class of practically interesting wave spectra all that is required to obtain the statistical distribution of the quiescent periods is simple rescaling.  相似文献   

Local meteoric water lines describe extratropical precipitation     

Devin F. Smith  Elsa Saelens  Deborah L. Leslie  Anne E. Carey 《水文研究》2021,35(2):e14059

Stable water isotopes δ¹⁸O and δ²H are used to investigate precipitation trends and storm dynamics to advance knowledge of precipitation patterns in a warming world. Herein, δ¹⁸O and δ²H were used to determine the relationship between extratropical cyclonic precipitation and local meteoric water lines (LMWLs) in the eastern Ohio Valley and the eastern United States. Precipitation volume weighted and unweighted central Ohio LMWLs, created with samples collected during 2012–2018, showed that temperature had the greatest effect on precipitation isotopic composition. HYSPLIT back trajectory modelling showed that precipitation was primarily derived from a mid-continental moisture source. Remnants of major hurricanes were collected as extratropical precipitation during the 2012–2018 sampling period in central Ohio. Extratropical precipitation samples were not significantly different from the samples that created the central Ohio LMWL. Six additional LMWLs were derived from United States Geological Survey (USGS) Atmospheric Integrated Research Monitoring Network (AIRMoN) samples collected in Pennsylvania, Delaware, Tennessee, Vermont, New Hampshire, and Oxford, Ohio. Meteoric water lines describing published samples from Superstorm Sandy, plotted with these AIRMoN LMWLs, showed isotopic composition of Superstorm Sandy precipitation was commonly more depleted than the average isotopic composition at the mid-latitude locations. Meteoric water lines describing the Superstorm Sandy precipitation were not significantly different in slope from LMWLs generated within 300 km of the USGS AIRMoN site. This finding, which was observed across the eastern Ohio Valley and eastern United States, demonstrated a consistent precipitation δ²H–δ¹⁸O relationship for extratropical cyclonic and non-cyclonic events. This work also facilitates the analysis of storm development based on the relationship between extratropical event signature and the LMWL. Analysis of extratropical precipitation in relation to LMWLs along storm tracks allows for stronger development of precipitation models and understanding of which climatic and atmospheric factors determine the isotopic composition of precipitation.  相似文献   

Evaluation of the temporal variations of groundwater storage and its interactions with climatic variables using GRACE data and hydrological models: A study from Turkey     

Behnam Khorrami  Orhan Gunduz 《水文研究》2021,35(3):e14076

Monitoring of the fluctuations of groundwater storage is particularly important in arid and semi-arid regions where water scarcity brings about various challenges. Remote sensing data and techniques play a preponderant role in developing solutions to environmental problems. The launch of Gravity Recovery and Climate Experiment (GRACE) satellites has eased the remote monitoring and evaluation of groundwater resources with an unprecedented precision over large scales. Within the scope of the current study, the latest release (RL06) of GRACE mass concentrations (Mascons) from Jet Propulsion Laboratory (JPL) dataset as well as Global Land Data Assimilation System (GLDAS) models of Noah and Catchment Land Surface Model (CLSM) were used to provide Groundwater Storage Anomalies (GWSA) over Turkey. The temporal interactions of the estimated GWSA with the climatic variables of precipitation and temperature (derived from the reanalysis datasets of CHELSA [Climatologies at High resolution for the Earth's Land Surface Areas] and FLDAS [the Famine Early Warning Systems Network Land Data Assimilation System], respectively) were investigated statistically. The results suggest that there is a descending trend (from 2003 to 2016) for Terrestrial Water Storage Anomalies (TWSA) and GWSA over Turkey with a total loss of 11 and 6 cm of water, respectively. The statistical analysis results also indicate that the monthly variations of GWSA over Turkey are highly correlated with precipitation and temperature at 2-month lag. The analysis of the climatology (long-term) values of monthly GWSA, precipitation and temperature also revealed high agreement between the variables.  相似文献   

各向异性介质的矢量波场分离与应用          下载免费PDF全文

芦俊  石瑛  杨春颖 《地球物理学报》2018,61(8):3310-3323

针对裂缝各向异性介质，本文提出一种非正交假设下的矢量波场分离方法.本文首先对多分量地震勘探中常见的波型泄漏现象进行了数学描述，提出在纵、横波波场分离的同时应该考虑恢复纵、横波的矢量振幅.为了对裂缝方位角与各向异性系数进行定量预测，本文将矢量波场分离拆分成三个步骤来实施：第一步，用Z、R两分量的仿射坐标系变换分离ZR平面内的P波投影与SV波；第二步，用ZR平面内的P波投影与T分量的仿射坐标系变换分离P波与SH波；第三步，用纯净的SV波与SH波的成像剖面分离快慢横波，并预测裂缝发育参数.模型数据与实际数据的试验结果表明，本文提出的纵、横波波场分离方法能够获得完整的矢量振幅信息，并提供裂缝预测的精度.  相似文献   

Multi‐Scale Fuzzy Inference System for Influent Characteristic Prediction of Wastewater Treatment          下载免费PDF全文

Zhiwei Cheng  Xuejiao Li  Yun Bai  Chuan Li 《洁净——土壤、空气、水》2018,46(7)

  相似文献   

Seismic electric signals in seismic prone areas          下载免费PDF全文

Nicholas V.Sarlis  Panayiotis A.Varotsos  Efthimios S.Skordas  Seiya Uyeda  Jacques Zlotnicki  Toshiyasu Nagao  Anatoly Rybin  Mary S.Lazaridou-Varotsos  Konstantina A.Papadopoulou 《地震科学（英文版）》2018,31(1):44-51

The Varotsos-Alexopoulos-Nomicos(VAN) method of short-term earthquake prediction was introduced in the 1980s. The VAN method enables estimation of the epicenter, magnitude and occurrence time of an impending earthquake by observing transient changes of the electric field of the Earth termed seismic electric signals(SES). Here, we present a few examples of SES observed in various earthquake prone areas worldwide.  相似文献